Ore-concentration process



' modifying agent is introduced into the ore- UNITED STATES BENJAMIN H. DOSENIBACEL OF BUTTE, MONTANA; EDNA M. DOSENBACH PATENT OFFICE.

' OF SAID BENJAMIN H. DOSENBACH, DECEASED.

ORE-CONCENTRATION PROCESS.

No Drawing.

To all whom it may concern:

Be it known that I, BENJAMIN H. DOSEN- BACH, a citizen of the United States, residing at Butte, in the county of Silver Bow and State of Montana, have invented certain new and useful Improvements in an Ore- Concentration Process, of which the followin is a specification.

lvly invention is an improvement in that form of the flotation process wherein the pulp in the gaseous form and generally in admixture with some other gas such as air..

By the term modifying agent I refer to the substance used for the purpose of promoting the preferential attraction of the gaseous bubbles for certain constituents of r the ore as distinguished from other constituents. When the modifying agent is 1ntroduced into the ore pulp in the gaseous form by mechanical agitation or through a porous medium such as canvas, unglazed earthenware, concrete or other porous material the gaseous modifying agent may either be the vapor of a substance that normally assumes the liquid or'solid form, that is, that assumes the liquid or solid format-theordinarily prevailing temperatures" and piessures or the gaseous modifying agent may be a permanent gas, that-is, a substance f-which normally exists in the gaseous form at ordinary tempereftureswpressures; A

great variety of substances may bensed as. modifying agents in the gaseous form, such.

as theproducts formed by gasifying many several metalliferous.constituents such asthei sulfids' of ir0n zinc and lead certain of the 7 metalligferous constituents may be floated tofthe almost complete exclusion of the others by the use of certain reagents which have a deterrent effect upon the flotation of some of the sulfid constituentsbut not upon others. The agent used for preventing the flotation of some of the metalliferous constituents may be either some salt or other substance added to and mixed with the ore Specification of Letters Patent.

pulp into which the gaseous modifying agent 1s introduced, or, in other instances may be some gas or vapor mixed with the modifyblende, the admixture of sulfur dioxid in proper amounts with the gaseous modifying agent has the effect of preventing the flotation of the blende while not interfering with the flotation of the galena. The amount of sulfur dioxid to be used in admixture with the gaseous modifying agent can only be determined by experimentation upon the particular ore being treated. Even in the case of a particular ore a quantitative determination by volume of the proportion of sulfur dioxid to modifying gas is diflicult, but the regulation itself is comparatively slmple if the sulfur dioxid be discharged into the current of modifying gas through a regulating valve or other controlling Patented May 10, 1921. Application filed November 16, 1917. Serial No. 202,268.

means. A satisfactorily-sharp separation of blende-iron; the sulfid of iron and galena can be effectedbythe means described and the residue containingthe blende can subsequently be c'oncent fated by flotation treatment, the effect of the sulfur dioxid in preventing the flotation ofthe blende being onl temporary.

Under certain conditions sulfuric acid in small amounts when added to theme pulp likewise. causes preferential flotation of one metalliferous constituent of a' mixed ore as distinguished from other constituents. For instance, in treating an ore containing sulfids of lead and zinc, a small amount of sulfuric acid almost completely prevents the flotation of the zinc sulfid, while not interfering with the flotation of the lead sulfid, and a subsequent treating of the residue under other conditions will bring about the flotation of the zinc sulfid.

Sodium hydrate or the hydrate of alkaline or alkaline earths when added to a pulp of zinc lead ore without acid has the effect, upon the introduction of the modifying as, of preventing the flotation of the zinc w ile not interfering with the flotation of the lead and the zinc contained in the residue can be floated in the subsequent operation in which sulfuric acid is added to, the pulp.

Sodium sulfhydrate (N aSH) has an action similar to that of sodium hydrate as a deterrent upon flotation of zinc sulfid in the presence of lead sulfid'and gangue. Other soluble'sulfur compoundsand a variety of other SubStances'haVe a similar deterrent efi'ect upon-the flotation of part of the metalliferousconstituents of mixed ores and my invention includes the'use of a gaseous modifylng agent, either a permanent gas or the vapor of .a normally liquid or soluble substance tending to bring about flotation of all of the metalliferous constituents of an ore together with the use of some deterrent agency acting to more or less completely prevent the flotation of part of the metalliferous constituents, such deterrent agencytaking the form either of some gas mixed with the modifying gas or some substance added to and mixed with thence pulp.

What .I claim is:

1. In a'proce'ss of flotation concentration of ores containing a plurality of floatable metalliferous constituents the operatlons of introducing into the ore pulp a gaseous modifying agent tending'to cause flotation of all of said" constituents and simultaneously introducing a gaseous substance which has a deterrent effect upon the flotation of some of the metalliferous constituents of the ore but not upon others.

2. In a process of flotation concentration of ores containing a plurality of floatable metalliferous constituents the operations of introducing. into the ore pulp a gaseous modifying agent tending to cause flotation of all of said constituents mixed with a gaseous substance which has a deterrent efdeterrent effect upon the flotation of some,

of the metalliferous constituents of the ore but not upon others.

In testimony whereof, I have subscribed my name.

BENJAMIN H. DOSENBAOH. 

